Various techniques for improving graininess of dye images of silver halide color light-sensitive materials are hitherto known. For example, Japanese Patent Publication No. 15495/74 discloses a technique wherein an intermediate layer containing gelatin is provided between a high sensitivity emulsion layer and a low sensitivity emulsion layer for the purpose of preventing influences of coarse grains in the high sensitivity emulsion layer. Further, U.S. Pat. No. 4,414,308 discloses a technique wherein an intermediate layer comprising light-insensitive gelatin containing a coupler, which develops the same hue as that developed by a coupler contained in a high sensitivity emulsion layer and has a coupling rate not higher than that of said coupler in the high sensitivity emulsion layer, is provided between the high sensitivity emulsion layer and the low sensitivity emulsion layer.
All of the light-sensitive materials employing these techniques are negative photographic materials that are subjected to negative processing and intended to be printed on positive materials such as print paper. Negative photographic materials generally have a layer structure in which the silver/coupler molar ratio in a high sensitivity emulsion layer is larger than that in a low sensitivity emulsion layer. However, there has been no consideration in the art of techniques applicable to a layer structure in which the silver/coupler molar ratio in a high sensitivity emulsion layer is smaller than that in a low sensitivity emulsion layer, which is usually employed in color reversal light-sensitive materials. Improvement of graininess by providing an intermediate layer as described above is possible only in the above-described layer structure employed in negative photographic materials because an oxidation product of a developing agent diffuses from the high sensitivity emulsion layer having larger grains into the low sensitivity emulsion layer due to the larger silver/coupler ratio of the high sensitivity emulsion layer and develops a color therein, thereby reducing graininess of the low sensitivity emulsion layer.
In color reversal light-sensitive materials, however, the silver/coupler ratio in a high sensitivity emulsion layer is generally smaller than that in a low sensitivity emulsion layer, so that the diffusion of an oxidation product of a developing agent takes place in the reverse direction to the case of the negative photographic materials, i.e., the oxidation product of a developing agent diffuses from the low sensitivity emulsion layer having a smaller grain size into the high sensitivity emulsion layer of poor graininess. Accordingly, a reduction of graininess due to diffusion of an oxidation product of a developing agent does not occur in the color reversal light-sensitive materials. Thus, a color reversal light-sensitive material having an intermediate layer between a high sensitivity emulsion layer and a low sensitivity emulsion layer has not hitherto been proposed.
However, the graininess of color reversal light-sensitive materials is still unsatisfactory, and further improvement in graininess is highly desired.